The invention relates to work enclosures, in particular to low temperature storage systems, and more particularly to very low temperature storage systems.
In order to conserve samples of blood derivatives, DNA fractions, or other living matter under good conditions, it is necessary for storage to take place at very low temperature, for example at about xe2x88x9280xc2x0 C. or xe2x88x9285xc2x0 C.
It is known to perform that type of storage using conventional freezers or even, when necessary, by means of bottles of liquid nitrogen for temperatures that are lower still.
Known freezers are of the same type as home freezers and they generally comprise a vertical door for a cupboard version or a horizontal door for a chest version.
Nevertheless, such freezers present at least two drawbacks for the above-mentioned storage, specifically:
opening the single door causes a large amount of heat to be exchanged between the stored substances and the outside air each time the door is opened, even if the door is opened solely for the purpose of inserting or removing a single article, thus leading to problems of the inside of the chest warming up and to frost forming; and
it is very difficult or even impossible to automate the transfer of articles of the kind that are generally placed in containers, specifically because there is only one door. Unfortunately, the quantity of articles stored and the frequency of access to said articles now justify or even require such freezers to be automated.
That is why the invention proposes an original system making it possible amongst other things to solve the above-mentioned drawbacks. Although it is particularly adapted to temperatures in the range xe2x88x9280xc2x0 C. to xe2x88x9285xc2x0 C., the present invention also applies to temperatures that are lower and indeed to temperatures that are higher. The invention can also be adapted to other working enclosures such as ovens, CO2 incubators, . . .
The invention thus provides an assembly comprising a work, first chamber and a sealed, second chamber provided with means for treating the air inside the second chamber, the inside of the first chamber defining a work space having means for creating a controlled atmosphere within the work space and at least one support for containers of articles to be placed in the work space, the first enclosure having a top plate with at least one access opening formed therethrough giving access to the work space to enable the support to be inserted therein and withdrawn therefrom, the support being provided with a shutter element of dimensions greater than the dimensions of the access opening so as to close the access opening under the effect of gravity when the support is placed in the work space through the access opening, the second enclosure being placed above the top plate of the first enclosure.
The invention also provides a work enclosure defining an internal work space and containing means for creating a controlled atmosphere inside the work space, and at least one support for article containers to be placed in the work space, the enclosure having a top plate with at least one access opening formed therethrough giving access to the work space to enable the support to be inserted therein and withdrawn therefrom, the support being provided with a shutter element for closing the access opening under the effect of gravity when the support is placed through the access opening into the work space, the enclosure having automatic means above the top plate for moving containers on the supports.
The invention also provides a work enclosure defining an inside work space and comprising means for creating a controlled atmosphere in the work space and at least one support for article containers to be placed in the work space, the enclosure comprising a top face with at least one access opening formed therethrough giving access to the work space to enable the support to be inserted therein and withdrawn therefrom, and shutter means for shutting the access opening, the support being provided with a shutter element for closing the access opening under the effect of gravity when the support is placed in the work space through the access opening, with the top plate being extended into the work space by a bottom skirt surrounding the access opening.